Psoriasis is a disease of the skin, whose etiology is unknown. The skin lesions associated with psoriasis may be described as dull red patches or plaques of scaly erythema. The scales are distinctive, having a slightly opalescent silvery appearance. The disease has a predilection for certain areas of the body; thus the scalp, the extensor surfaces of the extremeties (particularly at the elbows and knees), the back and the buttocks are most usually affected. However, the nails, eyebrows, axillae, umbilicus and anogenital regions are also frequent cites of involvement.
To date, there has been no report of a complete and permanent cure for psoriasis, and although the several treatments of choice available afford temporary remission of the symptoms, recurrence is almost certain. Most treatments involve the topical application of steroid (e.g. the adrenocortical steroids) ointments and creams, and no clinically successful, long-term, systemic treatment for the disease is currently available.
The compounds utilized in the process of the invention, substituted benzylideneaminoguanidines and their pharmacologically acceptable acid addition salts, have previously been described in the literature. For example, Belgian Patents 722,109 and 722,136 disclose pharmaceutical compositions containing these compounds which are hypotensive, antibacterial, CNS active, analgesic, diuretic, and antiinflammatory agents; and British Patent 1,019,120 discloses the use of these compounds as herbicidal agents. In addition the preparation of the substituted benzaldehydes from which the benzylideneaminoguanidines of the invention may be prepared is described in Chemical Abstracts, 26, 1271 (1931); 31, 3816 (1936).